private static bool UpdateEffects(object uobject, DragEventArgs e)
{
IDropTargetAdvisor advisor = GetDropTargetAdvisor(uobject as DependencyObject);
if (advisor.IsValidDataObject(e.Data) == false)
{
return(false);
}
if ((e.AllowedEffects & DragDropEffects.Move) == 0 &&
(e.AllowedEffects & DragDropEffects.Copy) == 0)
{
e.Effects = DragDropEffects.None;
return(true);
}
if ((e.AllowedEffects & DragDropEffects.Move) != 0 &&
(e.AllowedEffects & DragDropEffects.Copy) != 0)
{
if ((e.KeyStates & DragDropKeyStates.ControlKey) != 0)
{
}
e.Effects = ((e.KeyStates & DragDropKeyStates.ControlKey) != 0) ?
DragDropEffects.Copy : DragDropEffects.Move;
}
return(true);
}
/// <summary>
/// Check if drag data is valid and update drag item preview with copy or move effects.
/// </summary>
/// <param name="sender">Drop area element.</param>
/// <param name="e">Contains arguments relevant to all drag-and-drop events.</param>
/// <returns>"True", if data is valid and copy or move effects are allowed.</returns>
private static bool UpdateEffects(UIElement sender, DragEventArgs e)
{
if (currentTargetAdvisor.IsValidDataObject(sender, e.Data) == false)
{
e.Effects = DragDropEffects.None;
e.Handled = true;
return(false);
}
if ((e.AllowedEffects & DragDropEffects.Move) == 0 &&
(e.AllowedEffects & DragDropEffects.Copy) == 0)
{
e.Effects = DragDropEffects.None;
return(false);
}
if ((e.AllowedEffects & DragDropEffects.Move) != 0 &&
(e.AllowedEffects & DragDropEffects.Copy) != 0)
{
// Note: default drag behavior are MOVE and Ctrl+Drag is COPY.
// Todo: make it configurable to be able to swap them
e.Effects = ((e.KeyStates & DragDropKeyStates.ControlKey) != 0)
?
DragDropEffects.Copy
: DragDropEffects.Move;
}
return(true);
}
static bool UpdateEffects(object sender, DragEventArgs e)
{
IDropTargetAdvisor advisor = GetDropTargetAdvisor(sender as FrameworkElement);
if (!advisor.IsValidDataObject(e.Data))
{
return(false);
}
// TODO: cope with Link, Scroll
if ((e.AllowedEffects & DragDropEffects.Move) == 0 &&
(e.AllowedEffects & DragDropEffects.Copy) == 0)
{
e.Effects = DragDropEffects.None;
return(false);
}
if ((e.AllowedEffects & DragDropEffects.Move) != 0)
{
e.Effects = DragDropEffects.Move;
}
if ((e.AllowedEffects & DragDropEffects.Copy) != 0)
{
if ((e.AllowedEffects & DragDropEffects.Move) == 0 || (e.KeyStates & DragDropKeyStates.ControlKey) != 0)
{
e.Effects = DragDropEffects.Copy;
}
}
return(true);
}